1. Field of the Invention
The present invention relates to an optical disc drive, and more particularly, to an optical disc drive using a noise reducing unit for reducing noise generated by air flow due to the rotation of a disc.
2. Description of the Related Art
Typically, optical disc drives are devices which write or read information by radiating light on an optical medium (hereinafter, referred to as an optical disc) having a disc shape, such as a compact disc (CD) or a digital versatile disc (DVD).
FIG. 1 shows a structure of a conventional optical disc drive. Referring to FIG. 1, the conventional optical disc drive includes a main frame 11, a tray 15, and a cover 18.
A spindle motor (not shown) is installed in the main frame 11. The spindle motor has a turntable 13, on which an optical disc D is mounted, and an optical pickup 14, which makes a reciprocating motion in a radial direction of the optical disc D, and records information on the optical disc D or reproduces the information recorded on the optical disc D. The main frame 11 includes a sub-chassis 12 which moves upwards and downwards with respect to the main frame 11.
The tray 15 is installed at the main frame 11 to be able to slide and includes a mounting portion on which the optical disc D is seated.
The cover 18 is installed to cover the top surface of the main frame 11. The cover 18 presses and supports the optical disc D mounted on the turntable 13.
The optical disc D, seated on the tray 15 and inserted into the main frame 11, is mounted on the turntable 13, supported by the clamper 19, and is rotated by the spindle motor (not shown) at high speed.
Noise generated by the high-speed rotation of an optical disc in a high-speed and high-density optical disc drive has been a serious problem in the development of high performance optical disc drives. The noise is generated as a result of various noise generating causes. These include, but are not limited to friction of the surface of the optical disc with air, a pressure difference between inner and outer circumferences of the optical disc, collision of air from an external surface of the optical disc with walls of an optical disc mounting portion disposed in a tray, and air turbulence around the rotating optical disc. The noise escapes through a gap between a door and a main body case, increasing the whole noise of the optical disc.